In a typical restaurant kitchen, a plurality of cooking units are lined up side by side in a row under a common exhaust hood. The cooking units may include, for example, ranges, griddles, fryers, and broilers. They all produce air laden with grease, smoke, fumes, moisture, and heat in varying amounts and temperatures. Low temperature cooking equipment such as ranges and griddles produce considerably less amounts of such pollutants in comparison to high temperature equipment such as broilers. Traditional ventilation apparatus are unable to adjust or regulate the airflow in segments within the filter area of the hood. Therefore, to exhaust all of the pollutants and heated air produced from the cooking equipment, traditional ventilation apparatus provide excess ventilation for cooking units such as ranges and griddles in order to capture the large quantities of pollutants produced by broilers and fryers. To increase efficiency, some have modified traditional kitchen ventilators with inlet throat choke attachments in air inlet regions associated with low-pollutant cooking units. The inlet throat choke attachments reduce or throttle the flow of air through portions of the ventilator where the maximum available rate of air removal is not required to remove the pollutants generated by the associated units. U.S. Pat. No. 4,281,635 issued Aug. 4, 1981 to Gaylord discloses one such kitchen ventilator.
The installation of the supplemental inlet throat choke attachments into an existing ventilation hood requires taking apart the ventilation apparatus. The installation, removal, and adjustment of the choke attachments are difficult and time-consuming. Further, pollutants such as grease and particulates carried by the air accumulate on the choke attachments and surrounding areas, which need to be cleaned periodically. Typical water-washed ventilation hoods employ water streams that cannot reach the different sides of the choke attachments disposed at various angles. The accumulation of the pollutants has a negative impact on the ventilation system, and creates unsanitary conditions and fuel for any fire within the ventilation apparatus. In addition, because there are different types and sizes of ventilation hoods and different attachments of the cooking units, the choke attachments will typically need to be custom-designed to achieve the maximum benefits.
Some have designed exhaust hoods that are adjustable to achieve improved ventilation. For instance, U.S. Pat. No. 5,522,377 to Fritz discloses an adjustable exhaust hood that includes an open underside and a grease filter defining an exhaust plenum between the hood and the grease filter and a flow path through the grease filter. A shutter-like panel is slidable into the flow path adjacent to the grease filter for blocking a portion of the flow path to adjust a volume of air flowing through the exhaust hood. Fritz also discloses the use of multiple side-by-side panels.
U.S. Pat. No. 5,960,786 to Lambertson discloses an adjustable cartridge filter for use in a cartridge ventilator hood. The filter has a front wall with a front wall opening and a back wall with a back wall opening. A flow diverter is disposed obstructively at the back wall opening and extends between the front wall and the back wall, causing a flow restriction between the front wall opening and the back wall opening. The flow diverter is adjustable to change the amount of the resistance generated by the cartridge and the size of the air passage through the cartridge filter.
The present invention provides a removable, adjustable ventilation cartridge filter for use in a cartridge ventilator to increase the efficiency of the ventilator by regulating and adjusting the air flow in segments corresponding to different associated cooking units and extracting the maximum amount of pollutants by maintaining high air speed within the cartridge. The cartridge filter has an adjustable flow diverter and choke to control the resistance and speed of the air flow through the cartridge. The cartridge filter fits easily into a track provided as part of a cartridge ventilation hood. As a result, the cartridge filter is easy to install and easy to remove for inspection, adjustment, or cleaning. The flow diverter extends sufficiently far in the space between the front wall opening and back wall opening such that a gas flows from the front wall opening through a front diverted spacing between the front wall and the flow diverter in a first direction, around a lower edge of the front diverter, through a back diverted spacing between the back wall and the flow diverter in a second direction which is substantially opposite from the first direction, to the back wall opening. The sharp angle of turn of about 180xc2x0 increases extraction of grease or other pollutants in the air flowing therethrough.
In accordance with an aspect of the present invention, an adjustable cartridge filter for use in a cartridge ventilator comprises a filter housing including a front wall having a front wall opening and a back wall coupled to and spaced from the front wall. The back wall includes an upper back wall portion spaced from a lower back wall portion by a back wall opening which is defined between an upper portion edge of the upper back wall portion and a lower portion edge of the lower back wall portion. A flow diverter is disposed obstructively at the back wall opening and is adjustably supported by the housing to move relative to the housing. The flow diverter has a front diverter portion which is disposed between the back wall opening and the front wall and which is spaced from the front wall to define a front diverted spacing. The flow diverter has a rear diverter portion which is adjustably coupled to the back wall to move the front diverter portion in a space between the front wall and the back wall to divert a flow of a gas from the front wall opening to the back wall opening, so that the gas flows from the front wall opening through the front diverted spacing between the front wall and the front diverter portion in a first direction, around a lower edge of the front diverter portion, through the rear diverted spacing between the back wall and the front diverter portion in a second direction which is substantially opposite from the first direction, to the back wall opening.
In some embodiments, the rear diverter portion is adjustably coupled to the back wall to block a portion of the back wall opening to define an adjustable choke spacing equal to a remaining portion of the back wall opening not blocked by the rear diverter portion. The flow diverter is movable between a first position where the rear interface of the flow diverter is disposed at the upper portion edge of the back wall opening and a second position where the rear interface of the flow diverter is disposed between the upper portion edge and the lower edge of the back wall opening with the rear diverter portion blocking a portion of the back wall opening from the upper portion edge of the back wall opening to the rear interface of the flow diverter.
In accordance with another aspect of the invention, an adjustable cartridge filter for use in a cartridge ventilator comprises a front wall having a front wall opening, and a back wall coupled to and spaced from the front wall. The back wall includes an upper back wall portion spaced from a lower back wall portion by a back wall opening which is defined between an upper portion edge of the upper back wall portion and a lower portion edge of the lower back wall portion. A flow diverter is disposed obstructively at the back wall opening and includes a front diverter portion which is disposed between the back wall opening and the front wall and which is spaced from the front wall to define a front diverted spacing and spaced from the back wall to define a rear diverted spacing. The cartridge filter further comprises means for movably coupling the flow diverter to the back wall to move the flow diverter in a space between the front wall and the back wall to divert a flow of a gas from the front wall opening to the back wall opening, so that the gas flows from the front wall opening through the front diverted spacing between the front wall and the front diverter portion in a first direction, around a lower edge of the front diverter portion, through the rear diverted spacing between the back wall and the front diverter portion in a second direction which is substantially opposite from the first direction, to the back wall opening.
In some embodiments, the means is configured to move the flow diverter to change the size of the back wall opening. The flow diverter is movable in a direction substantially parallel to the front wall and the back wall.
In accordance with another aspect of the invention, a cartridge ventilator comprises a ventilator hood, and a cartridge filter housed in the ventilator hood. The cartridge filter comprises a filter housing including a front wall having a front wall opening and a back wall coupled to and spaced from the front wall and having a back wall opening. The cartridge filter further comprises a flow diverter disposed obstructively at the back wall opening and having a front diverter portion spaced from the front wall to define a front diverted spacing and spaced from the back wall to define a rear diverted spacing. The flow diverter has a rear diverter portion coupled to the front diverter and blocking a portion of the back wall opening to define a choke spacing equal to a remaining portion of the back wall opening not blocked by the rear diverter portion. The front diverter portion extends in a space between the front wall and the back wall to divert a flow of a gas from the front wall opening to the back wall opening, so that the gas flows from the front wall opening through the front diverted spacing between the front wall and the front diverter portion in a first direction, around a lower edge of the front diverter portion, through the rear diverted spacing between the back wall and the front diverter portion in a second direction which is substantially opposite from the first direction, to the back wall opening. A rear choke portion is coupled to the ventilation hood and obstructively spaced from the choke spacing.
In some embodiments, the rear choke portion comprises a generally flat surface being larger in area than the choke spacing. The rear choke portion is adjustably coupled to the ventilation hood to move relative to the back wall and choke spacing. The flow diverter is adjustably supported by the filter housing to adjust the choke spacing.